Is there really a problem with the presence of Pharmaceutical Products (PPs) in the environment? This is one of the main questions the scientific community has been trying to answer in recent years.

In spite of the exponentially- increasing number of scientific papers, national and international reports, workshops and conferences, there remains a need for discussions and debates aimed at identifying the key issues to be addressed in order to better understand and manage the risks of PPs in the environment for both humans and wildlife.

In terms of risk to human health, there is a tendency to consider it to be negligible, given that drinking water is the main source of exposure and that PP concentration in water is between a million-fold and a billion-fold below the level of therapeutic doses. But what about other sources of exposure (food, fish, soil, etc.)? On the contrary to risk for humans, environmental risk is admitted to, with some effects bring described in the literature - such as fish feminization, bird decline, genotoxic effects on wildlife and fish behaviour modification - even though a recent study investigating more than 50 active ingredients showed that for 95% of them, environmental risk is not significant.

Uncertainty is thus a reality, in terms of both human and ecological risk assessment, due in particular to the limited number of studies (especially for human health) on the one hand, and to the lack of certain data required for robust risk calculation on the other. A workshop organized as part of the PHARMAS EU project recently attempted to identify, prioritize and quantify the main sources of these uncertainties by distinguishing between model uncertainties, fundamental uncertainties or non-quantifiable uncertainties. Expert discussions have established a list of 100 questions, classifying the 20 most important ones into several categories such as prioritization of substances, pathways of exposure , bioavailability and uptake, effects characterization, risk and relative risk, and risk management.

Within this context, an international conference entitled “Pharmaceuticals in the Environment: is there a problem?”. This conference, organized in Nimes, France by the LERES Biodiagnostic Unit of the French School of Public Health (EHESP) on June 3–4th 2013, aimed to bring answers to influence areas of risk assessment, water management and pharmaceutical production as well as regulatory affairs and public perception - not just in terms of human and wildlife health, but also from a regulatory and social perspective.

More than a hundred participants, from research institutes, sanitary agencies, water companies, academic research groups, the pharmaceutical industry, and other organisations attended the three oral sessions completed by a poster exhibition. In the course of the 2-day conference, 50 communications were presented, offering new information and data on European-level actions, environmental and human risk assessment of pharmaceuticals, perspectives on problem assessment and future actions.

A Special Issue of Chemosphere will be published early in 2014. It brings together selected papers presented at this event (the whole proceedings are available upon request to the corresponding author) and deals with risk assessment and management, including toxicity and hazard characterization, fate and behaviour of parent molecule and transformation products. Papers in this special issue also serve to increase our knowledge and understanding regarding the difficult identification and quantification of the potential risk PPs represent for humans and the environment.